Question: ${6 \div 0.4 = {?}}$
$ {6 \div 0.4 = 6 \div \dfrac{4}{10}} $ $ {\phantom{6 \div 0.4} = 6 \div \dfrac{2}{5}} $ Dividing by a fraction is the same as multiplying by the reciprocal of the fraction. $ {6 \div \dfrac{2}{5} = 6 \times \dfrac{5}{2}} $ $ {\phantom{6 \div \dfrac{2}{5}} = \dfrac{6 \times 5}{2}} $ $ {\phantom{6 \div \dfrac{2}{5}} = \dfrac{30}{2}} $ $ {\phantom{6 \div \dfrac{2}{5}} = 15} $